package com.ly.common.utils.ip;

import java.net.InetAddress;
import java.net.UnknownHostException;
import javax.servlet.http.HttpServletRequest;

import com.ly.common.utils.StringUtils;
import com.ly.common.utils.html.EscapeUtil;

/**
 * 获取IP方法
 * @author ruoyi
 */
public class IpUtils {
    public static String getIpAddr (HttpServletRequest request) {
        if ( request == null ) {
            return "unknown";
        }
        String ip = request.getHeader ( "x-forwarded-for" );
        if ( ip == null || ip.length () == 0 || "unknown".equalsIgnoreCase ( ip ) ) {
            ip = request.getHeader ( "Proxy-Client-IP" );
        }
        if ( ip == null || ip.length () == 0 || "unknown".equalsIgnoreCase ( ip ) ) {
            ip = request.getHeader ( "X-Forwarded-For" );
        }
        if ( ip == null || ip.length () == 0 || "unknown".equalsIgnoreCase ( ip ) ) {
            ip = request.getHeader ( "WL-Proxy-Client-IP" );
        }
        if ( ip == null || ip.length () == 0 || "unknown".equalsIgnoreCase ( ip ) ) {
            ip = request.getHeader ( "X-Real-IP" );
        }

        if ( ip == null || ip.length () == 0 || "unknown".equalsIgnoreCase ( ip ) ) {
            ip = request.getRemoteAddr ();
        }
        return "0:0:0:0:0:0:0:1".equals ( ip ) ? "127.0.0.1" : EscapeUtil.clean ( ip );
    }

    public static boolean internalIp (String ip) {
        byte[] addr = textToNumericFormatV4 ( ip );
        return internalIp ( addr ) || "127.0.0.1".equals ( ip );
    }

    private static boolean internalIp (byte[] addr) {
        if ( StringUtils.isNull ( addr ) || addr.length < 2 ) {
            return true;
        }
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        // 10.x.x.x/8
        final byte SECTION_1 = 0x0A;
        // 172.16.x.x/12
        final byte SECTION_2 = (byte) 0xAC;
        final byte SECTION_3 = (byte) 0x10;
        final byte SECTION_4 = (byte) 0x1F;
        // 192.168.x.x/16
        final byte SECTION_5 = (byte) 0xC0;
        final byte SECTION_6 = (byte) 0xA8;
        switch ( b0 ) {
            case SECTION_1:
                return true;
            case SECTION_2:
                if ( b1 >= SECTION_3 && b1 <= SECTION_4 ) {
                    return true;
                }
            case SECTION_5:
                switch ( b1 ) {
                    case SECTION_6:
                        return true;
                }
            default:
                return false;
        }
    }

    /**
     * 将IPv4地址转换成字节
     * @param text IPv4地址
     * @return byte 字节
     */
    public static byte[] textToNumericFormatV4 (String text) {
        if ( text.length () == 0 ) {
            return null;
        }

        byte[] bytes = new byte[4];
        String[] elements = text.split ( "\\.", - 1 );
        try {
            long l;
            int i;
            switch ( elements.length ) {
                case 1:
                    l = Long.parseLong ( elements[0] );
                    if ( ( l < 0L ) || ( l > 4294967295L ) ) {
                        return null;
                    }
                    bytes[0] = (byte) (int) ( l >> 24 & 0xFF );
                    bytes[1] = (byte) (int) ( ( l & 0xFFFFFF ) >> 16 & 0xFF );
                    bytes[2] = (byte) (int) ( ( l & 0xFFFF ) >> 8 & 0xFF );
                    bytes[3] = (byte) (int) ( l & 0xFF );
                    break;
                case 2:
                    l = Integer.parseInt ( elements[0] );
                    if ( ( l < 0L ) || ( l > 255L ) ) {
                        return null;
                    }
                    bytes[0] = (byte) (int) ( l & 0xFF );
                    l = Integer.parseInt ( elements[1] );
                    if ( ( l < 0L ) || ( l > 16777215L ) ) {
                        return null;
                    }
                    bytes[1] = (byte) (int) ( l >> 16 & 0xFF );
                    bytes[2] = (byte) (int) ( ( l & 0xFFFF ) >> 8 & 0xFF );
                    bytes[3] = (byte) (int) ( l & 0xFF );
                    break;
                case 3:
                    for ( i = 0; i < 2; ++ i ) {
                        l = Integer.parseInt ( elements[i] );
                        if ( ( l < 0L ) || ( l > 255L ) ) {
                            return null;
                        }
                        bytes[i] = (byte) (int) ( l & 0xFF );
                    }
                    l = Integer.parseInt ( elements[2] );
                    if ( ( l < 0L ) || ( l > 65535L ) ) {
                        return null;
                    }
                    bytes[2] = (byte) (int) ( l >> 8 & 0xFF );
                    bytes[3] = (byte) (int) ( l & 0xFF );
                    break;
                case 4:
                    for ( i = 0; i < 4; ++ i ) {
                        l = Integer.parseInt ( elements[i] );
                        if ( ( l < 0L ) || ( l > 255L ) ) {
                            return null;
                        }
                        bytes[i] = (byte) (int) ( l & 0xFF );
                    }
                    break;
                default:
                    return null;
            }
        } catch ( NumberFormatException e ) {
            return null;
        }
        return bytes;
    }

    public static String getHostIp () {
        try {
            return InetAddress.getLocalHost ().getHostAddress ();
        } catch ( UnknownHostException e ) {
        }
        return "127.0.0.1";
    }

    public static String getHostName () {
        try {
            return InetAddress.getLocalHost ().getHostName ();
        } catch ( UnknownHostException e ) {
        }
        return "未知";
    }
}